This is an old revision of this page, as edited by PetesGuide(talk | contribs) at 00:39, 27 January 2020(Undid revision 933354433 by 2.137.180.30 (talk) because no citation given and code QMS not found at http://www.pilotfriend.com/training/flight_training/communication/q_code.htm or other listings of Q signals.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.Revision as of 00:39, 27 January 2020 by PetesGuide(talk | contribs)(Undid revision 933354433 by 2.137.180.30 (talk) because no citation given and code QMS not found at http://www.pilotfriend.com/training/flight_training/communication/q_code.htm or other listings of Q signals.)
The Aeronautical Code signals are radio signal codes. They are part of a larger set of Q Codes allocated by the ITU-R. The QAA–QNZ code range includes phrases applicable primarily to the aeronautical service,[2] as defined by the International Civil Aviation Organisation.
First defined in ICAO publication "Doc 6100-COM/504/1" in 1948 and in "ICAO Procedures for Air Navigation Services, Abbreviations and Codes (PAN
a S-ABC)" [Doc8400-4] (4th edition 1989), the majority of the Q codes have slipped out of common use; for example today reports such as QAU ("I am about to jettison fuel") and QAZ ("I am flying in a storm") would be voice or computerized transmissions. But several remain part of the standard ICAO radiotelephony phraseology in aviation.
Atmospheric pressure at sea level in the International Standard Atmosphere (ISA), equal to 1013.25 mbar or hPa and used as reference for measuring the pressure altitude. When flight levels are used as an indication of altitude, 1013.25 hPa is used as mean sea level (QNH).
Atmospheric pressure at mean sea level (may be either a local, measured pressure or a regional forecast pressure (RPS)). When set on the altimeter it reads altitude.
